Zusammensetzung und Dichte der Harnstoffschmelze und der koexistierenden Gasphase

Fluide Mischphasen und Phasengleichgewicht

Abstract

An experimental method for the determination of the composition and density of the coexisting phases in the vapour-liquid carbon dioxide/ammonia/water equilibrium system at high pressure and temperature is presented. Apart from the elemental analysis of the vapour phase, which required a specially developed sampling procedure, the chemical analyses were carried out by ordinary analytical methods. For the measurement of the vapour phase density, a high pressure high temperature gas pycnometer from a high alloy stainless steel was used. Results, including the concentration of urea in the vapour phase and of ammonium carbamate in the liquid phase are given for a charge density of 0.53 g/cm³, at a temperature of 170 °C, and initial NH₃:CO₂ and H₂O:CO₂ molar ratios of 2 and 0, resp.